1. Field of the Invention
This invention relates to a method of casting concrete structural elements. More particularly, the invention relates to an improved casting method for economically casting differing complex-shaped concrete crypt modules for mausoleum structures of the type disclosed in our U.S. Pat. No. 3,878,656, entitled "Modular Mausoleum Crypt System."
2. Description of the Prior Art
In recent years there has been increasing emphasis placed on the efficient utilization of land, especially for burial purposes in areas where the population growth has been significant. One particular pressing problem which has received attention for at least the past two decades is the use of above-ground mausoleums, similar in concept to highrise apartments. The advantages of the above-ground, multi-level mausoleums are readily seen since this concept permits a more efficient utilization of land and has the added advantage of permitting visitors to be indoors while paying respects to the deceased.
Heretofore, a variety of construction techniques have been employed to construct multi-level, above-ground mausoleums. One such technique utilizes a "poured-in-place" method used in apartment construction. Thus, concrete is poured in forms on the construction site, level by level, until the entire structure is completed. In this manner, a multi-story mausoleum can be fabricated according to a predetermined design. This approach yields a highly satisfactory product but is economically undesirable by virtue of the slow and relatively expensive construction technique employed.
A variety of techniques for casting concrete structural elements in a shaped form are known. One technique for casting relatively large reinforced concrete components is to initially fabricate a wooden form and cast therein a concrete pattern of the shape of the ultimately desired component. A final concrete form is then fabricated by pouring concrete within a wall constructed around the concrete pattern which is removed when the concrete sets. A significant disadvantage of this technique is that the concrete form is entirely inflexible. Unless very accurately controlled drafts of substantial magnitudes are used, removal of the cast component from such an inflexible concrete form results in damage to the form or the cast component, or both.
Others have utilized forms fabricated from metal plate for casting concrete structural elements. However, this approach utilized rigid, heavy metal plates to prevent deformation of the form and consequent difficulty in releasing the element as well as undesirable dimensional distortion thereof. Even though a degree of form flexibility is achieved with a metal plate form, release and removal of the element is still time-consuming and is not satisfactory in all cases involving complex shapes.
To overcome some of the foregoing difficulties encountered when removing a cast concrete element from a form, others have suggested the use of a plurality of separate and detachable sections which, when assembled, receive the poured concrete. To extract the finished element from the form, the form is broken down. Utilization of such forms is obviously time-consuming and unless the mating sections of the form are well fitted and reasonably rigid, the fluent casting material will leak out from the form at the adjoining surfaces of the sections. This disadvantageously results in rapid accumulation of concrete flash and debris on the assembly or production line.
A further significant disadvantage of all the above prior art techniques is the lack of flexibility in providing forms for casting differently configured components. Using the aforementioned prior art techniques of a concrete pattern cast in a wooden form or metal plate forms, a plurality of separate forms is required for components having the same basic structure but having slightly different configurations, such as, for example, the interlocking members of the crypt modules illustrated and described in our aforementioned U.S. Pat. No. 3,878,656. Somewhat more flexibility may be possible with forms fabricated with detachable, variously-configured sections, however, the efficient utilization of such detachable sections is still severely limited by the need to build up the form for casting and subsequently to break down the form to extract the completed component.